1. Field of the Invention
The present general inventive concept relates to an image forming apparatus. More particularly, the present general inventive concept relates to a toner supplying apparatus to supply an image forming apparatus with toner.
2. Description of the Related Art
Generally, some types of image forming apparatuses are supplied with toner for development by a separate toner supplying apparatus holding a predetermined amount of toner. When the separate toner supplying apparatus holding the predetermined amount of the toner is mounted to a predetermined position of the image forming apparatus, the toner is supplied to the image forming apparatus.
FIG. 1 is a view illustrating a conventional toner supplying apparatus used in an image forming apparatus.
Referring to FIG. 1, the toner supplying apparatus 1 includes a toner tank 10 and a supplying part 11. The supplying part 11 is formed in a substantially hollow cylindrical shape and projects inside the toner tank 10. A toner outlet 13 for discharging toner is provided at an outer surface of the supplying part 11. A toner-conveying device (not illustrated) that conveys toner in the toner tank 10 into the supplying part 11 is provided at a side of the supplying part 11. Also, a rotation shaft 15 is rotatably disposed at a center of the toner tank 10, and a toner agitating film 17 is fixed to the rotation shaft 15 to agitate the toner. At this time, the toner agitating film 17 has a width corresponding to an inner length L1 of the toner tank 10, exclusive of a width of the supplying part 11. Also, a driving gear 19 is disposed at an end of the rotation shaft 15 so that when the toner supplying apparatus 1 is mounted to the image forming apparatus (not illustrated), the rotation shaft 15 can be supplied with a rotation force by the image forming apparatus.
Therefore, when the toner supplying apparatus 1 is mounted to the image forming apparatus (not illustrated), the driving gear 19 rotates the rotation shaft 15 so that the toner agitating film 17 fixed to the rotation shaft 15 rotates. When the toner agitating film 17 rotates, the toner in the toner tank 10 is agitated to move downward to the toner-conveying device (not illustrated). Then, the toner-conveying device conveys the toner into the supplying part 11, so that the toner is discharged outside of the toner tank 10 through the toner outlet 13. A toner inlet 21 is provided under the toner outlet 13 and is in fluid communication with a developing unit 23 of the image forming apparatus. Therefore, the toner discharged through the toner outlet 13 falls into the toner inlet 21, is transported to the developing unit 23 of the image forming apparatus, and develops images.
However, the conventional toner supplying apparatus 1 with the above-described structure has a lot of toner left in the toner tank 10 when the toner of the toner supplying apparatus 1 is determined to have “run out” of toner, even though the toner agitating film 17 rotates to agitate the toner. This problem (i.e., a lot of toner left in the toner tank 10 when the toner of the toner supplying apparatus 1 is determined to have “run out” of toner) is caused by the structure of the toner supplying apparatus 1. In other words, because the toner supplying apparatus 1 has the supplying part 11 projecting inside the toner tank 10, the toner agitating film 17 cannot agitate the whole (entire) inner space of the toner tank 10, and as a result, some of the toner is left in the toner tank 10. In other words, the toner agitating film 17 agitates the toner in the inner space of the toner tank 10 except for a location on a surface of the supplying part 11 projecting inside the toner tank 10, so that the toner near the supplying part 11 cannot be moved to the outside thereof and instead remains inside the toner tank 10. If a lot of the toner remains in the toner tank 10, a toner using efficiency of the toner supplying apparatus 1 is decreased. As a result, a printing cost is increased. Also, discarding the toner remaining in the toner supplying apparatus 1 may cause environmental pollution.